1. Field of the Invention
The present invention relates to a liquid container in which a liquid such as ink is stored, and an ink jet recording method of discharging ink droplets to record an image on a recording material, and more particularly, it relates to a liquid container to be detachably mounted on an ink jet recording device.
2. Description of the Related Art
Heretofore, a recording device which records an image on a recording material such as paper, cloth, a plastic sheet or a sheet for OHP has been proposed as a configuration on which various recording devices such as recording heads of a wire dot system, a thermal sensitive system, a thermal transfer system and an ink jet recording system can be mounted.
Among these systems, as a small-noise non-impact recording system, the ink jet recording system to discharge ink from a discharge port (a nozzle) arranged on a recording element and record the image on the recording material is incorporated in an ink jet recording device. The device can perform a high-density and high-speed recording operation.
The ink jet recording device employs a constitution corresponding to a function and a use configuration inherent in the system to which this recording device is applied. In general, the ink jet recording device includes a carriage on which an ink jet recording head is mounted, an ink tank as a liquid container which supplies ink to the recording head, a conveyance mechanism which conveys recording paper, and a control section which controls these components.
Moreover, the recording head which discharges ink droplets from a plurality of discharge ports is serially scanned in a direction (a main scanning direction) crossing a conveyance direction (a sub scanning direction) of recording paper. On the other hand, when the recording is not performed, the recording paper is intermittently conveyed (pitch conveyance) as much as an amount equal to a recording width. When the recording head including a large number of nozzles linearly arranged in parallel with the sub scanning direction to discharge ink is used and the recording head is scanned once on the recording paper, the recording is performed as much as a width corresponding to the number of the nozzles.
Moreover, since the ink jet recording device incurs a small running cost, the recording device can be miniaturized. Furthermore, the device can easily record a color image by use of a plurality of colors of ink.
For the above reasons, the ink jet recording device is used as an output unit of an information system, for example, a printer as an output terminal of a photocopier, a facsimile machine, an electronic typewriter, a word processor, a work station or the like. Alternatively, the ink jet recording device is used as a handy or portable printer disposed at a personal computer, an optical disk drive, a video device or the like.
On the other hand, as an energy generation element which allows the recording head to discharge the ink from the discharge ports, an electromechanical conversion member such as a piezo element is used. Alternatively, a liquid is heated by an electrothermal conversion element having a heating resistor member.
Above all, according to the recording head of the ink jet recording system in which the ink droplets are discharged using thermal energy, since the discharge ports are highly densely arranged, the image can be recorded with high resolution. Above all, when the electrothermal conversion element is used as the energy generation element in the recording head, the heat is easily miniaturized. Moreover, merits of the recording head can sufficiently be used in an IC technology and a micro processing technology which have remarkably advanced and have improved reliability thereof in a semiconductor field in recent years. The recording head using the electrothermal conversion element is advantageous because the head can highly densely be mounted easily, and manufactured with low cost.
The ink tank usually includes a storage bag in which the ink to be supplied to the recording head is stored, a joint portion to be connected to the ink jet recording device, and a housing in which these components are incorporated. In the ink jet recording device, preliminary discharge is performed in order to prevent an initial discharge defect after the recording head is left to stand for a short time period. Also in the device, an ink sucking operation from the recording head left to stand for a long time period is periodically performed in order to prevent non-discharge due to mixed bubbles after the recording head is left to stand for the long time period.
Waste ink generated by the preliminary discharge and the periodic ink suction from the recording head is discharged into the ink jet recording device. In order to miniaturize the whole ink jet recording device, the conventional ink tank includes a waste ink absorption member in which the waste ink generated by the preliminary discharge and the periodic ink suction is collected and stored. This waste ink absorption member is incorporated in the housing.
That is, the waste ink which has originally been discharged into the ink jet recording device is absorbed by the waste ink absorption member, and the member is arranged in the ink tank. According to such a constitution, the ink jet recording device can be miniaturized. Furthermore, the ink tank is replaced with a new ink tank at a time when the ink to be supplied to the recording head is consumed. That is, when the ink tank is replaced, the waste ink absorption member disposed in the ink tank is replaced with a new member. Therefore, even in a case where it is constituted that the waste ink absorption member is incorporated in the ink tank, the ink tank is inhibited from being excessively enlarged.
As the constitution in which the waste ink absorption member is incorporated in the ink tank to miniaturize the recording device, a constitution is disclosed in which the waste ink absorption member is incorporated in the ink tank and further the recording device includes a unit to distribute the waste ink to a plurality of ink tanks (see Japanese Patent Application Laid-Open No. 2003-127433). In this constitution, since the waste ink is distributed to the plurality of ink tanks by the recording device, the whole recording device can be miniaturized.
In this type of ink jet recording device, when the waste ink is collected in the ink tank, the waste ink needs to be securely absorbed by the waste ink absorption member disposed in the ink tank. In a case where the waste ink is not absorbed or stored in the waste ink absorption member to cause existence of floating ink, the ink might leak from the ink tank. To prevent such ink leakage, in the conventional ink tank, a joint portion for the waste ink via which the waste ink is introduced into the ink tank needs to be hermetically closed with a rubber seal or the like. This structure is one cause for increase of the manufacturing cost of the ink tank.